Solar-induced chlorophyll fluorescence (SIF) and photochemical reflectance index (PRI) are expected to be useful for remote sensing of photosynthetic activity at various spatial scales. This review discusses how chlorophyll fluorescence and PRI are related to the CO₂ assimilation rate at a leaf scale. Light energy absorbed by photosystem II chlorophylls is allocated to photochemistry, fluorescence, and heat dissipation evaluated as non-photochemical quenching (NPQ). PRI is correlated with NPQ because it reflects the composition of xanthophylls, which are involved in heat dissipation. Assuming that NPQ is uniquely related to the photochemical efficiency (quantum yield of photochemistry), photochemical efficiencies can be assessed from either chlorophyll fluorescence or PRI. However, this assumption may not be held under some conditions such as low temperatures and photoinhibitory environments. Even in such cases, photosynthesis may be estimated more accurately if both chlorophyll fluorescence and PRI are determined simultaneously. To convert from photochemical efficiency to CO₂ assimilation, environmental responses in stomatal conductance also need to be considered. Models linking chlorophyll fluorescence and PRI with CO₂ assimilation rates will contribute to understanding and future prediction of the global carbon cycle.

预计太阳诱导的叶绿素荧光（SIF）和光化学反射指数（PRI）可用于遥感各种空间尺度的光合作用。这篇评论讨论了叶绿素荧光和PRI如何与CO _2相关联叶尺度的同化率。光系统II叶绿素吸收的光能分配给光化学，荧光和散热，以非光化学猝灭（NPQ）评估。PRI与NPQ相关，因为它反映了参与散热的叶黄素的成分。假设NPQ与光化学效率（光化学的量子产率）唯一相关，则可以从叶绿素荧光或PRI评估光化学效率。但是，在某些条件下（例如低温和光抑制环境）可能无法保持该假设。即使在这种情况下，如果同时测定叶绿素荧光和PRI，则可以更准确地估算光合作用。从光化学效率转换为CO ₂同化时，还需要考虑气孔导度的环境响应。将叶绿素荧光和PRI与CO ₂同化率联系起来的模型将有助于理解和预测全球碳循环。